package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @author: HuangQi
 * @date: Created in 18:14 2023/9/5
 * @description: 登录检查过滤器
 */
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {


    private static final AntPathMatcher ANT_PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        log.info("拦截到请求:{}", request.getRequestURI());

        //获取请求的uri
        String uri = request.getRequestURI();

        //定义不需要拦截的url
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login"
        };

        //检查本次请求是否需要放行
        boolean check = check(uri, urls);

        //如果需要放行,则放行
        if (check) {
            log.info("本次请求:{}需要放行", uri);
            filterChain.doFilter(request, response);
            return;
        }

        //如果不需要放行,则检查session中是否有登录信息
        if (request.getSession().getAttribute("employee") != null) {
            //如果有登录信息,则放行
            log.info("用户已登录,用户id为:{}", request.getSession().getAttribute("employee"));
            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);
            filterChain.doFilter(request, response);
            return;
        }

        if (request.getSession().getAttribute("user") != null) {
            //如果有登录信息,则放行
            log.info("用户已登录,用户id为:{}", request.getSession().getAttribute("user"));
            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);
            filterChain.doFilter(request, response);
            return;
        }

        log.info("用户未登录");
        //如果没有登录信息,通过输出流方式向客户端页面响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    /**
     * 路径匹配,检查本次请求是否需要放行
     *
     * @param requestURI
     * @param urls
     * @return
     */
    public boolean check(String requestURI, String[] urls) {
        for (String url : urls) {
            boolean match = ANT_PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
